title: Perfectly planar boronyl boroxine D3h B6O6: a boron oxide analog of boroxine and benzene.
abstract: Inorganic benzene-like compounds such as boroxine and borazine are of interest in chemistry. Here we report on theoretical prediction of a new member of the inorganic benzene family: boronyl boroxine. This perfectly planar D3h B6O6 (1, (1)A1') cluster is identified as the global minimum of the system at density functional theory (B3LYP) and molecular orbital theory levels, which lies at least ∼20 kcal∕mol lower in energy than alternative structures. It can be formulated as B3O3(BO)3 and features a boroxol B3O3 ring as the core with three boronyl (BO) groups attached terminally, closely resembling boroxine and obtainable from the latter via isovalent BO∕H substitution. Detailed bonding analyses reveal weak π aromaticity in boronyl boroxine, rendering it a true analog to boroxine and borazine. Upon electron attachment, the slightly distorted C2v B6O6(-) (2, (2)A2) anion is also perfectly planar, and its electronic properties are calculated. A huge energy gap (4.83 eV) is predicted for B6O6(-) (2) at B3LYP level, which is characteristic of a stable closed-shell neutral cluster. Similar to benzene, boronyl boroxine is also predicted to be an effective inorganic ligand to form sandwich-type complexes, such as D3d [B3O3(BO)3]2Cr (4, (1)Ag).
authors.affiliation: Institute of Molecular Science, Shanxi University, Taiyuan 030006, Shanxi, People's Republic of China.
authors.forename: Da-Zhi
authors.initials: DZ
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Bai
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Haigang
authors.initials: H
authors.lastname: Lu
authors.forename: Hua-Jin
authors.initials: HJ
authors.lastname: Zhai
authors.forename: Si-Dian
authors.initials: SD
authors.lastname: Li
mesh_terms: D001554:Benzene / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D001896:Boron Compounds; C042168:boron oxide; D001554:Benzene